THIS is where the long climb back begins, where maybe rehabilitation meets redemption. Stephon Marbury has some reparations to pay, to his team, to his teammates, to his coach, to the fans who have booed him ceaselessly in the two weeks since he took his one-game leave of absence from the season.

The fact that his benching in Phoenix may have been misguided will never make up for his petulance. That’s on Marbury’s permanent record, and there it will remain. But if he hopes to salvage his career as a Knick, and he has steadfastly insisted that’s what he wants, it will be games like this one that will offer him that chance.

Marbury selected the perfect night to turn in his finest performance of the year, a pulsating 113-109 win over the Utah Jazz at a jazzed-up Madison Square Garden. For the length of his tenure in New York, Marbury has always served as the perfect foil for the parade of elite point guards who pass through the turnstiles here each year: Kidd, Nash, Davis, Parker.

Always, it seems, Marbury has been their straight man.

Always, it seems, these are nights when everyone is reminded of everything that Marbury once promised but never delivered, everything he is not, the pure point guard who never developed an affinity for that role. This time, it was Deron Williams, who is as enjoyable a player as there is to watch in the NBA. And Williams was very, very good last night: 26 points, eight assists, with a handle that can mesmerize you.

But Marbury was better.

It wasn’t just the numbers: 28 points and six assists. And it wasn’t just the fact that the Knicks were able to hold on at the end, giving them a fourth Garden win and the faithful a renewed sense of the possibilities lurking within this complicated roster.

“You could tell he was playing with a purpose,” said Williams, who along with Chris Paul anchors the NBA’s newest wave of elegant point guards. “He’s still one of the quickest guards in the league, and a challenge to play against, and he outplayed me tonight.”

Isiah Thomas, who toppled the first domino in Marbury’s world on an Arizona-bound airplane two weeks ago by removing him from the starting lineup, said the way Marbury stood up and stood in against Williams reminded him of his own advanced NBA years, when a fresh breed of point guard led by Tim Hardaway liked to bring it to the veterans to see how they measured up.

“The old guard,” Thomas said, “and the new guard.”

And on this night, the old guard responded with as good a game as he’s ever played as a Knick, especially given the stiff challenge on the other side of the floor. That’s something new. Kidd has bedeviled Marbury constantly. Baron Davis walked into the Garden last week and absolutely schooled him.

It was three years ago when Marbury set himself up terribly with his observation that he was the best point guard in the NBA, and he’s had an awful time living up to that statement, and living it down. Last night was a pleasing reminder of all that he’s capable of being, and doing.

“I just did what I always do,” Marbury said, and even he has to know that’s not entirely true. On his off nights, he’s still as electrifying a player as the Knicks own, but the Knicks don’t necessarily need electrifying. They need a point guard. And Knicks fans needed to see their own point guard play at an elite level when challenged, rather than suffer from another acute case of playmaker envy.

“You can coach him hard,” Thomas said, and if what we saw last night is the belated result of Marbury being coached as hard as he’s ever been in his life, then maybe the entire Phoenix fiasco really can become something of a flashpoint in his career – and in the coach’s tenure.

It was Thomas, after all, who all but promised that he would be he one to finally draw the inner Cousy out of Marbury when he arranged for this shotgun marriage. Last night, at last, with something to prove in the worst way, we finally saw that. So did Deron Williams.